A193475 a(n) = 4*16^n - 2*4^n.

2, 56, 992, 16256, 261632, 4192256, 67100672, 1073709056, 17179738112, 274877382656, 4398044413952, 70368735789056, 1125899873288192, 18014398375264256, 288230375614840832, 4611686016279904256, 73786976286248271872, 1180591620683051565056

Offset: 0

Author

Peter Luschny, Aug 07 2011

Keywords

• nonn

Links

• Peter Luschny, The lost Bernoulli numbers.
• Index entries for linear recurrences with constant coefficients, signature (20, -64).

Programs

Maple

A193475 := proc(n) 2^(2*n+1); %^2; % - %% end: seq (A193475(n), n=0..20);

Formula

Recurrence: a(0) = 2, a(1) = 56, a(n) = 20*a(n-1) - 64*a(n-2).

G.f.: (16*x+2)/(64*x^2-20*x+1).

E.g.f.: 4*exp(16*x) - 2*exp(4*x).